scholarly journals Electrical Conductivity and Chemical Equilibria of Coordination Biopolymeric Cerium (IV)-Alginate Complex with Correlation between the Structure and Complex Stability

2015 ◽  
Vol 7 (2) ◽  
pp. 57 ◽  
Author(s):  
Ishaq Zaafarany ◽  
Hatem Altass ◽  
Jabir Alfahemi ◽  
Khalid Khairou ◽  
Refat Hassan
Keyword(s):  
Electrical Conductivity ◽  
Conduction Mechanism ◽  
Research Study ◽  
Coordination Geometry ◽  
Complex Stability ◽  
X Ray Diffraction ◽  
Chemical Equilibria ◽  
X Ray ◽  
Infrared Absorption Spectra ◽  
Diffraction Patterns

In this research study, the cross-linked cerium (IV)-alginate complex, as coordination biopolymeric compound in the granules form, was prepared. It has been indicated from the x-ray diffraction patterns that the nature of alginate complex is amorphous. Additionally, it has been revealed from the infrared absorption spectra that cerium (IV) chelates the alginate macromolecular chains in the complex. The study has displayed that the range of us OCO- is 1424 cm-1and the range of uasOCO- is 1605 cm-1. This indicates that a complexation type between the cation Ce4+ and both carboxylate and hydroxyl functional groups of alginate macromolecule is usually takes place. The study has also measured the electrical conductivity (s) of coordination biopolymeric cerium (IV)-alginate complex, as function of temperature. It has been indicated from the measured value of the electrical conductivity, i.e., 1.04 x10-9 Siemens at 20oC that the conductance of the complex lies in the range of semiconductors. The research has profoundly discussed with evaluation of the thermodynamic parameters. Afterwards, appropriate conduction mechanism based on the electrical conductivity and chemical equilibrium has also been suggested and discussed in terms of the complex stability in correlation with its coordination geometry.

Effects of Donor Doping on Microstructure and Electrical Properties of Bismuth Layer-Structured Bi4Ti3O12 Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 259-262 ◽  
Author(s):  
Lina Zhang ◽  
Su Chuan Zhao ◽  
Liao Ying Zheng ◽  
Guo Rong Li ◽  
Qing Rui Yin
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Electrical Properties ◽  
Ferroelectric Properties ◽  
Orthorhombic Phase ◽  
X Ray Diffraction ◽  
Suitable Candidate ◽  
X Ray ◽  
Donor Doping ◽  
Diffraction Patterns

A study was conducted on the effects of donor dopants, Nb2O5 and WO3, on microstructure and electric properties of Bi4Ti3O12 (BIT) ceramics. X-ray diffraction patterns of the materials showed a single orthorhombic phase structure. The microstructure results revealed the appearance of plate-like grain. The donor doping decreased the conductivity of BIT by as much as 3 orders of magnitude. The dielectric and ferroelectric properties of doped-BIT materials were also investigated. The decrease in the electrical conductivity allowed the doped samples to be poled to develop piezoelectricity. Thermal annealing studies of the samples indicated the donor-doped BIT were suitable candidate materials for high-temperature piezoelectric applications.

Effect of CuO-TiO2 Eutectic on Thermal and Electrical Conductivities of CaCu3Ti4O12 Ceramics

2016 ◽  
Vol 881 ◽  
pp. 117-122
Author(s):  
Flavia dos Reis Gonçalves ◽  
Daniel Thomazini ◽  
Maria Virginia Gelfuso
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Laser Flash ◽  
Eutectic Phase ◽  
Flash Method ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrical Conductivities ◽  
Diffraction Patterns

In this work, CaCuxTiyO12 ceramics (2.7 ≤ x ≤ 3.3 and 3.25 ≤ y ≤ 4.75), related to excess and deficiency of CuO-TiO2 eutectic phase have been synthesized by coprecipitation method. The crystalline phases in the ceramics were identified by X-ray diffraction patterns, and the pellets have mainly presented CCTO and also exhibited CuO, TiO2 and CaTiO3 as secondary phases. The thermal conductivity of the ceramics was determined using the laser flash method in the temperature range of 300-1000 K. It was observed a decrement in thermal conductivity values as the amount of the eutectic phase decreased. The electrical DC conductivity has been measured by the two-probe method from 300-1000 K and it has been noted that both grain size and amount of eutectic phase influenced the electrical conductivity results.

scholarly journals Structural and Dielectric Properties of (1-x) (Al0.2La0.8TiO3) + (x) (BiZnFeO3) (x = 0.2 - 0.8) Nanocomposites

2021 ◽  
Author(s):  
A. Mallikarjuna ◽  
N. Suresh Kumar ◽  
T. Anil Babu ◽  
S. Ramesh ◽  
Chandra Babu Naidu K
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Phase Transformation ◽  
Dielectric Properties ◽  
Dielectric Behavior ◽  
Perfect Absorber ◽  
X Ray Diffraction ◽  
Ac Electrical Conductivity ◽  
X Ray ◽  
Diffraction Patterns

Abstract (1-x) (Al0.2La0.8TiO3) + (x) (BiZnFeO3) (x = 0.2 - 0.8) [ALTBZFO] nanocomposites were synthesized via hydrothermal method. The X-ray diffraction patterns indicated the phase transformation from tetragonal to cubic for x = 0.2 to 0.4 - 0.8 samples, respectively. The surface morphology showed the existence of nanospheres like structures. At 1 MHz frequency also, the dielectric constant was increased from 230 to 710 for x = 0.2 – 0.6 samples, respectively. But, interestingly, x = 0.6 nanocomposite exhibited the negative dielectric behavior having the dielectric constant (ε') ~ -58.5 and dielectric loss (ε") ~ -417 at 8 MHz. Likewise, x = 0.6 sample showed ac-electrical conductivity (σac) -0.159 S/cm at 6 MHz. Hence, these kinds of materials can provide high charge stored capacitor, and perfect absorber applications.

STRUCTURE-PROPERTIES RELATION OF CO-DOPE BISMUTH LAYER-STRUCTURED Bi3.25La0.75(Ti1-xWx)3O12 CERAMICS

2009 ◽  
Vol 23 (31n32) ◽  
pp. 3793-3799
Author(s):  
PASINEE SIRIPRAPA ◽  
ANUCHA WATCHARAPASORN ◽  
SUKANDA JIANSIRISOMBOON
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Lattice Distortion ◽  
Ferroelectric Properties ◽  
Doping Content ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Structure Properties

In this work, fabrication and investigation of substituing high-valence W 6+ for Ti 4+ ion on B -site of La 3+-doped Bi 4 Ti 3 O 12 or BLT structure to form Bi 3.25 La 0.75( Ti 1-x W x)3 O 12 or BLTW (when x = 0, 0.01, 0.03, 0.05 0.07, 0.09 and 0.10) ceramics were carried out. X-ray diffraction patterns of BLTW ceramics indicated orthorhombic structure with lattice distortion, especially with higher concentration of WO 3 dopant. An increase in WO 3 doping content reduced not only length and thickness of grain, but also density of the ceramics. Electrical conductivity was found to decrease, while dielectric constant increased with W 6+ doping. Ferroelectric properties were found to be improved with increasing WO 3 content and were optimized at x = 0.05.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

Control of the phase composition of advanced calcium phosphates using an x-ray diffractometer with a curved position-sensitive detector

2020 ◽  
Vol 86 (6) ◽  
pp. 29-35
Author(s):  
V. P. Sirotinkin ◽  
O. V. Baranov ◽  
A. Yu. Fedotov ◽  
S. M. Barinov
Keyword(s):  
Phase Composition ◽  
Calcium Phosphates ◽  
Position Sensitive Detector ◽  
Sensitive Detector ◽  
X Ray Diffraction ◽  
X Ray ◽  
Impurity Phases ◽  
Position Sensitive ◽  
Diffraction Peaks ◽  
Diffraction Patterns

The results of studying the phase composition of advanced calcium phosphates Ca10(PO4)6(OH)2, β-Ca3(PO4)2, α-Ca3(PO4)2, CaHPO4 · 2H2O, Ca8(HPO4)2(PO4)4 · 5H2O using an x-ray diffractometer with a curved position-sensitive detector are presented. Optimal experimental conditions (angular positions of the x-ray tube and detector, size of the slits, exposure time) were determined with allowance for possible formation of the impurity phases during synthesis. The construction features of diffractometers with a position-sensitive detector affecting the profile characteristics of x-ray diffraction peaks are considered. The composition for calibration of the diffractometer (a mixture of sodium acetate and yttrium oxide) was determined. Theoretical x-ray diffraction patterns for corresponding calcium phosphates are constructed on the basis of the literature data. These x-ray diffraction patterns were used to determine the phase composition of the advanced calcium phosphates. The features of advanced calcium phosphates, which should be taken into account during the phase analysis, are indicated. The powder of high-temperature form of tricalcium phosphate strongly adsorbs water from the environment. A strong texture is observed on the x-ray diffraction spectra of dicalcium phosphate dihydrate. A rather specific x-ray diffraction pattern of octacalcium phosphate pentahydrate revealed the only one strong peak at small angles. In all cases, significant deviations are observed for the recorded angular positions and relative intensity of the diffraction peaks. The results of the study of experimentally obtained mixtures of calcium phosphate are presented. It is shown that the graphic comparison of experimental x-ray diffraction spectra and pre-recorded spectra of the reference calcium phosphates and possible impurity phases is the most effective method. In this case, there is no need for calibration. When using this method, the total time for analysis of one sample is no more than 10 min.

Infrared spectroscopic study of the YPO4-YCrO4 system

1985 ◽  
Vol 50 (10) ◽  
pp. 2139-2145
Author(s):  
Alexander Muck ◽  
Eva Šantavá ◽  
Bohumil Hájek
Keyword(s):  
Spectroscopic Study ◽  
Infrared Spectra ◽  
Point Of View ◽  
Mixed Crystals ◽  
Crystal Symmetry ◽  
Infrared Spectroscopic Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infrared Spectroscopic ◽  
Diffraction Patterns

The infrared spectra and powder X-ray diffraction patterns of polycrystalline YPO4-YCrO4 samples are studied from the point of view of their crystal symmetry. Mixed crystals of the D4h19 symmetry are formed over the region of 0-30 mol.% YPO4 in YCrO4. The Td → D2d → D2 or C2v(GS eff) correlation is appropriate for both PO43- and CrO43- anions.

scholarly journals Deep learning for visualization and novelty detection in large X-ray diffraction datasets

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Lars Banko ◽  
Phillip M. Maffettone ◽  
Dennis Naujoks ◽  
Daniel Olds ◽  
Alfred Ludwig
Keyword(s):  
Thin Film ◽  
Crystal Structure ◽  
Artificial Intelligence ◽  
Deep Learning ◽  
Novelty Detection ◽  
Structural Similarity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Post Hoc

AbstractWe apply variational autoencoders (VAE) to X-ray diffraction (XRD) data analysis on both simulated and experimental thin-film data. We show that crystal structure representations learned by a VAE reveal latent information, such as the structural similarity of textured diffraction patterns. While other artificial intelligence (AI) agents are effective at classifying XRD data into known phases, a similarly conditioned VAE is uniquely effective at knowing what it doesn’t know: it can rapidly identify data outside the distribution it was trained on, such as novel phases and mixtures. These capabilities demonstrate that a VAE is a valuable AI agent for aiding materials discovery and understanding XRD measurements both ‘on-the-fly’ and during post hoc analysis.

scholarly journals Simultaneous Multi-Bragg Peak Coherent X-ray Diffraction Imaging

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 312
Author(s):  
Florian Lauraux ◽  
Stéphane Labat ◽  
Sarah Yehya ◽  
Marie-Ingrid Richard ◽  
Steven J. Leake ◽  
...  
Keyword(s):  
Bragg Reflection ◽  
Volume Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Substrate ◽  
In Series ◽  
Diffraction Imaging ◽  
Diffraction Patterns ◽  
Lattice Planes ◽  
Oriented Parallel

The simultaneous measurement of two Bragg reflections by Bragg coherent X-ray diffraction is demonstrated on a twinned Au crystal, which was prepared by the solid-state dewetting of a 30 nm thin gold film on a sapphire substrate. The crystal was oriented on a goniometer so that two lattice planes fulfill the Bragg condition at the same time. The Au 111 and Au 200 Bragg peaks were measured simultaneously by scanning the energy of the incident X-ray beam and recording the diffraction patterns with two two-dimensional detectors. While the former Bragg reflection is not sensitive to the twin boundary, which is oriented parallel to the crystal–substrate interface, the latter reflection is only sensitive to one part of the crystal. The volume ratio between the two parts of the twinned crystal is about 1:9, which is also confirmed by Laue microdiffraction of the same crystal. The parallel measurement of multiple Bragg reflections is essential for future in situ and operando studies, which are so far limited to either a single Bragg reflection or several in series, to facilitate the precise monitoring of both the strain field and defects during the application of external stimuli.

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